Zinc
brass
If an element is missing one electron, which is defined as having a negative charge, then the element is a positively charged ion. If an element gains an extra electron, it will have a negative charge and be a negative ion. An element with an equal number of positively charged protons and negatively charged electrons is considered to be a neutral element (in other words, no charge). By the way, no charge for this answer!
As an element oxygen is neutral, but it forms negative ions.
potassium
Fluorine.
We find carbon or graphite as the center electrode of a zinc-carbon battery. It's the "common" battery we use in lots of stuff (but not an alkaline battery). That center electrode is the positive one, and the zinc makes up the outer or negative electrode in this battery. In an alkaline battery, manganese dioxide is the center, or the cathode (positive electrode). Powdered zinc will be found as the outer or negative electrode (anode).
Zinc
brass
carbon
Carbon is the reference element for the definition of the mole. In electrochemistry, the reference element/electrode is the Hydrogen electrode and all electrode potentials are against the hydrogen standard.
The element forming at the cathode will depend on what elements are present. Reduction takes place at the cathode, so whatever element is being reduced, that is the one that will be produced at the cathode.
current flows from the negative to the positive cable and back into the battery cells, recombining with the element depleted of electrons that are flowing out the negative cable. The process is not 100% efficient and the battery will eventually cease producing current.
alloy
When a capacitor is discharging, current is flowing out of the capacitor to other elements in the circuit, similar to a battery. Current flowing out of an element, by convention, is defined as negative current, while current flowing into an element, such as a resistor, is defined as positive current. Thus a discharging capacitor will always have a negative current.
Sodium's electron configuration means that there is just one electron in its outer shell, when becoming an Ion it is easier for it to "donate" this electron to the element it is forming a compound with. This means that the Sodium ion is no longer electrically balanced (it has lost a negatively charged electron) and becomes overall positively charged. Being positively charged it will of cause be attracted to the NEGATIVE electrode as oposite charges attract and similar charges repel.
No merc is not in a car battery
The electrode at which a reduction reaction occurs.PhysicsA cathode is the element of an electron tube from which electrons flow. Back in the day, current was thought to be positive, but we understand things differently now. In the "old school" version, the cathode was the element into which positive charges flowed. But that's usually not what is taught for the simple reason that it's a classical physics approach and isn't at all as useful as the idea that the cathode is the element from which electrons leave to go to the plate.In a two-element tube, the cathode has a compliment called the anode, or plate. Electrons flow from the cathode to the anode. Not the other way. There are tubes with three, four, and more elements, but they have these two basic elements.ChemistryThe cathode is the electrode of a polarized electrical device, such as a galvanic cell, out of which positive electric current flows. In a battery like the one in a vehicle, the positive terminal is the cathode. The car battery, which is a lead-acid battery, also has an electrode that is the compliment to the cathode: the anode. It's the negative terminal of the battery, and positive electric current flows into this electrode.The Wikipedia article on the cathode covers both the chemistry application of the term as well as the physics application, and a link is provided.